Monte Carlo investigation of optimal device architectures for SiGe FETs

Strained silicon channel FETs grown on virtual SiGe substrates show clear potential for RF applications, in a material system compatible with silicon VLSI. However, the optimisation of practical RF devices requires some care. 0.1-0.12 μm gate length designs are investigated using Monte Carlo techniques. Although structures based on III-V experience show fT values of up to 94 GHz, more realistic designs are shown to be limited by parallel conduction and ill constrained effective channel lengths. Aggressively scaled SiGe devices, following state-of-the-art CMOS technologies, show fT values of up to 80 GHz

Simple approach to include external resistances in the Monte Carlo simulation of MESFETs and HEMTs

The contact and external series resistances play an important role in the performance of modern 0.1-0.2 μm HEMT's. It is not possible to include these resistances directly into the Monte Carlo simulations. Here we describe a simple and efficient way to include the external series resistances into the Monte Carlo results of the intrinsic device simulations. Examples of simulation results are given for a 0.2 μm pseudomorphic HEMT

Strain engineered In_xGa_1-xAs channel pHEMTs on virtual substrates: a simulation study

The impact of In<sub>x</sub>Al<sub>1-x</sub>As strain control buffers on the performance of low In content InGaAs channel pseudomorphic high electron mobility transistor p(HEMT) is investigated. It is shown that relaxed and tensile strained channel devices outperform the conventional compressively strained channel devices. It is argued that strain engineering in GaAs based devices makes it possible to realise RF characteristics comparable to InP based pHEMTs while obtaining improved breakdown characteristics

RF performance of strained Si MODFETs and MOSFETs on "virtual" SiGe substrates: A Monte Carlo study

No abstract avaliable

Hematologic, hepatic, and renal function changes in hospitalized patients with Middle East respiratory syndrome coronavirus

Background There are no longitudinal data on the changes in hematologic, hepatic, and renal function findings in patients with Middle East respiratory syndrome coronavirus (MERS‐CoV) infection. Methods This is a retrospective cohort study of 16 MERS‐CoV patients, to describe the hematological, hepatic, and renal findings of patients with MERS‐CoV. Results During the 21 days of observation, there was no significant change in the hepatic panel or creatinine tests. There was a significant increase in the mean ± SD of the white blood cell count from 8.3 ± 4.6 to 14.53 ± 7 (P value = 0.001) and an increase in mean ± SD of the absolute neutrophil count from 6.33 ± 4.2 to 12 ± 5.5 (P value = 0.015). Leukocytosis was observed in 31% (5/16) of the patients on day 1 and in 80% (4/5) on day 21. Transient leukopenia developed in 6% (1/16) of the patients on day 1 and in 13% (1/8) on day 8. None of the patients had neutropenia. Lymphopenia was a prominent feature with a rate of 44% (7/16) of the patients on day 1 and 60% (3/5) on day 21. Lymphocytosis was not a feature of MERS‐CoV infection. Thrombocytopenia developed in 31% (5/16) of the patients on day 1 and 40% (2/5) on day 21. Thrombocytosis was not a prominent feature and was observed in 6% (1/16) of the patients on day 1 and 17% (1/6) on day 9. Conclusions Patients with MERS‐CoV infection showed variable hematologic parameters over time. Lymphocytosis and neutropenia were not features of MERS‐CoV infection

Graphene-like optical light field and its interaction with two-level atoms

The theoretical basis leading to the creation of a light field with a hexagonal honeycomb structure resembling graphene is considered along with its experimental realization and its interaction with atoms. It is argued that associated with such a light field is an optical dipole potential which leads to the diffraction of the atoms, but the details depend on whether the transverse spread of the atomic wave packet is larger than the transverse dimensions of the optical lattice (resonant Kapitza-Dirac effect) or smaller (optical Stern-Gerlach effect). Another effect in this context involves the creation of gauge fields due to the Berry phase acquired by the atom moving in the light field. The experimental realization of the light field with a honeycomb hexagonal structure is described using holographic methods and we proceed to explore the atom diffraction in the Kapitza-Dirac regime as well as the optical Stern-Gerlach regime, leading to momentum distributions with characteristic but different hexagonal structures. The artificial gauge fields too are shown to have the same hexagonal spatial structure and their magnitude can be significantly large. The effects are discussed with reference to typical parameters for the atoms and the fields

Complete Monte Carlo RF analysis of 'real' short-channel compound FET's

A comprehensive RF analysis technique based on ensemble Monte Carlo (EMC) simulation of compound FET's with realistic device geometry is presented. Y-parameters are obtained through Fourier transformation of the EMC transients in response to small changes in the terminal voltages. The terminal currents are statistically enhanced and filtered to allow for reliable y-parameters extraction. Improved analytic procedure for extracting the intrinsic device small-signal circuit components is described. As a result, stable y-parameters and reliable circuit components can he extracted for the whole range of device operation voltages. Parasitic components like contact and gate resistances are included in the y-parameters at a post processing stage to facilitate the forecast of the performance figures of merit of real devices. The developed RF technique has been applied in the EMC simulation of pseudomorphic HEMT's (pHEMT's) fabricated at the Glasgow Nanoelectronics Research Center. Good agreement has been achieved between the simulated and measured small-signal circuit components and performance figures of meri

Practice implications of an antimicrobial stewardship intervention in a tertiary care teaching hospital, Qatar

Background: Antibiotic misuse is a worldwide public health problem and has been associated with increased morbidity, length of hospital stay, mortality, healthcare costs, and most importantly antibiotic resistance. Aims: We aimed to evaluate the compliance of antibiotic prescribing with national guidelines, assess how educational interventions can best be utilized to make impact and fill gaps for optimal antibiotic utilization, and to identify facilitators and barriers to implementing ASPs in Qatar. Methods: Six cross-sectional baseline audits of antibiotic prescribing were conducted over a two-week period at a tertiary care teaching hospital. A sub-analysis of prescriptions with follow up has followed. An educational intervention utilizing the PDSA (Plan-Do-Study-Act) tool was implemented to address gaps identified. A repeated audit was done to assess the impact of change. Lastly, interviews were conducted to recognize perceived facilitators and barriers for ASP implementation, identify strategies to overcome barriers, and evaluate the effectiveness of educational interventions. Results: The most common indication for antibiotic prescribing was febrile neutropenia (20.7%). The most frequently used class of antibiotics was carbapenems (21.4%). Sixty percent of prescriptions complied with guidelines. The rationale behind choosing not to adhere to guidelines was not documented in 37.2% of cases. Suboptimal documentation in records was targeted through our intervention. The audit post intervention showed slight improvement in documentation. Facilitators and barriers included: collaboration and communication among teams, compliance with guidelines, interventions documented by clinical pharmacists, and electronic system errors. Conclusions: Effective communication, continuous documentation in records, and repetitive education promote rational antibiotic prescribing and enhance ASPs.This report was made possible by a UREP award [UREP18-033-3-010] from the Qatar National Research Fund (a member of The Qatar Foundation)

Exploitation of Phenotypic Variations Among some Barley (Hordeum vulgare L.) Genotypes for grain yield Under Irrigated Conditions of Sudan

Barley in Sudan is grown in limited areas for grain and forage, although the barley is a well adapted crop to Sudan environment, it has a very small number of genotypes. Therefore, this study aims at the exploitation of  phenotypic variations among the barley (Hordeum vulgare L.) genotypes in Sudan for possible utilization in breeding programmes and to identify the top yielding genotypes. A set of twenty barley genotypes were tested at three sites representing different environments of Sudan. The experiments were executed over two consecutive seasons (2010/2011 and 2011/2012) in a Randomized Complete Block Design (RCBD) with three replications. The results of the growth habit demonstrated that all the genotypes were resistant to lodging except the genotype 20 (local genotype) was susceptible to lodging. The results of the combined analysis showed very highly significant differences among the barley genotypes at three sites. Across the three sites, the common genotypes out-yielded the check were G3, G8 and G9. At Gezira, the genotypes G3, G8 and G9 out yielding the check by 31, 24 and 40%, respectively, at Hudeiba high terrace soil by 34, 9 and 31%, respectively, while at Hudeiba karu soil by 61, 21 and 20%, respectively. According to the ASV (AMMI Stability Value) concept, the most stable genotype was the check Beladi having an ASV of 4.5 with the lowest mean seed yield (1970 kg/ha). In contrast, the most unstable genotype was G3 with an ASV of 37.7, however, it had the highest grain yield (2810 kg/ha). Among the six environments, when the genotypes were arranged according to AMMI estimate, genotype G3 ranked first in four environments (Gezira in season 2011, karu in two seasons and high terrace soil in season 2011), genotype G9 ranked first in one environment (Gezira in season 2010) and ranked third in the other five environments, while genotype G8 ranked second in the high terrace soil in season 2010 and fourth in two environments (Gezira in two seasons). The check Beladi did not appear in the first four ranking genotypes. Therefore, the genotypes G3, G8 and G9 could provide a good option for barley seed yield under Sudan conditions.   يزرع الشعير في السودان في مناطق محدودة بغرض إنتاج الحبوب والأعلاف، على الرغم من أن الشعير محصول جيد التأقلم  في البيئات المناخية المختلفة  للسودان، إلا أن هنالك عددا قليلا جدًا من الطرز الوراثية التي تزرع فيه. لذلك، تهدف هذه الدراسة إلى إستغلال الاختلافات المظهرية بين بعض الطرز الوراثية للشعير (Hordeum vulgare L.) في السودان لإمكانية استخدامها في برامج التربية ولتحديد الطرز الوراثية الاعلي إنتاجية. تم اختبار عدد عشرين من الطرز الوراثية للشعير في ثلاثة مواقع تمثل بيئات مختلفة في السودان. تم تنفيذ التجارب على مدار موسمين متتاليين (2010/2011 و 2011/2012) باستخدام تصميم القطاعات العشوائية الكاملة (RCBD) بثلاثة مكررات. أظهرت نتائج التحليل المشترك تباين كبير للغاية بين الطرز الوراثية للشعير من حيث الإنتاجية في الثلاثة مواقع، حيث كانت الطرز الوراثية الشائعة التي فاقت إنتاجيتها الصنف المحلي هي G3 و G8 و G9 . في الجزيرة، الطرز الوراثية G3 و G8 و G9 فاقت إنتاجيتها الصنف المحلي بنسبة 31 و 24 و 40٪ على التوالي، أما في أراضي التروس العليا (الحديبة)  بنسبة 34 و 9 و 31٪ على التوالي، بينما في أراضي الكرو (الحديبة) بنسبة 61 و 21 و 20٪، على التوالي. وفقًا لمفهوم قيمة الثبات (ASV) كان الطراز الوراثي الأكثر ثباتًا هو الصنف المحلي بقيمة ثبات4.5  وبأقل متوسط ​​إنتاجية للبذور (1970 كجم / هكتار). في المقابل، كان الطراز الوراثي الأقل ثباتًا هو       G3 بقيمة ثبات  37.7، ومع ذلك، فقد حقق أعلى إنتاجية للحبوب (2810 كجم / هكتار). عند ترتيب الطرز الوراثية وفقًا لتقدير  AMMI في البيئات الست، احتل الطراز الوراثي G3 المرتبة الأولى في أربع بيئات (الجزيرة في موسم 2011 ، اراضي الكرو (الحديبة) في موسمين وفي اراضي التروس العليا (الحديبة) في موسم 2011) ، بينما احتل الطراز الوراثي G3  المرتبة الأولى في بيئة واحدة (الجزيرة) في موسم 2010) واحتل المرتبة الثالثة في البيئات الخمسة الأخرى، في حين احتل الطراز الوراثي G8 المركز الثاني في اراضي التروس العليا (الحديبة) في موسم 2010 والرابع في بيئتين (الجزيرة في موسمين). لم يظهر الصنف المحلي ضمن الطرز الوراثية الأربعة الأولى. أوضحت هذه النتائج أن الطرز الوراثية  G3 و G8 و G9 يمكن أن تكون خيارًا جيدًا لإنتاج بذور الشعير تحت ظروف السودا